Disintegrating training ammunition for firearms



May 28, 1968 w. JUNGERMANN DISINTEGRATING TRAINING AMMUNITION FOR FIREARMS Filed May 5, 1967 fl II United States Patent 3,385,215 DISINTEGRATING TRAINING AMMUNITEON FOR FIREARMS Werner Jungermann, Karlsruhe, Baden, Germany, as-

signor to Industrie-Werke Karlsruhe Alctiengesellschaft, Baden, Germany, a corporation of Germany Filed May 5, 1967, S81. No. teaser Claims priority, application Germany, May 17, 1966,

5 Claims. of. 10242.7

ABSTRACT 0F THE DISCLGSURE The invention relates to a disintegrating projectile, in particular to a disintegrating bullet for practice ammunition, comprising a casing preferably made of a plastics material and a filling of a metal powder or at least a core of compacted metal powder.

Disintegrating projectiles having a casing or jacket which encloses a metal powder filling or a core of campacted metal powder are known. Such projectile casings are made preferably of plastics, for instance thermoplastic synthetic resins such as polyethylene or polystyrene. The projectile casing must safely hold together the projectile during its passage through the barrel of the firearm upon firing, and must also assure a complete disintegration of the projectile and an unimpeded dispersion of its filling after leaving the barrel of the firearm.

In projectiles having a core of compacted metal powder for a filling it was found that upon firing such a projectile the rising powder gas pressure imparts a strong acceleration to the plastic portions of the projectile casing which are lighter in weight than the filling of the projectile, while the filling due to its inherent mass moment of inertia lags behind. This may result in the formation of cracks in the region where the projectile base merges with the cylindrical casing wall and may even lead to a complete shearing away of the base portion from the casing. This gives rise to the possibility of an undesirable disintegration of the projectile in the barrel of the firearm and the result would be an excessive wear on or even damage to the barrel.

The object of this invention is to overcome the aforedcscribed disadvantages of known projectiles of the mentioned type. It is a further object of the invention to improve the sealing of the rear portion of the projectile between it and the rifled portion of the gun barrel.

In accordance with the invention, this problem is solved by providing a semi-elastic seal in the rear end of the projectile casing and have the rear end of the projectile filling supported by it. The semi-elastic seal according to the invention is arranged between the projectile base which is integrally connected with the rear end of the cylindrical projectile casing and the rear end of the projectile filling.

According to another feature of the invention, the semielastic seal consists of a metal powder loosely filling the hollow space between the projectile base and the rear end of the projectile filling.

3,385,215 Patented May 28, 1968 The projectile casing may in known manner have at least one guide band radially projecting from the circumference of its cylindrical rear portion and the semi-elastic seal may-viewed in the direction of movement of the projectile-be arranged behind the guide band on the circumference of the cylindrical casing, which guide band upon firing of the firearm engages the grooves in the barrel of the firearm.

It is also an object of the invention to reduce the thickness of the wall of the rear portion of the projectile casing in the region of the metal powder filling forming the semielastic seal, as compared to the wall thickness of the remaining portions of the projectile casing.

The elastic seal deposited between the rear end of the projectile filling, e.g. a core of compacted metal powder, and the projectile base possesses a certain load absorbing property. Therefore the projectile filling is able to make a limited movement toward the projectile base when the projectile is accelerated by the propellant gases acting upon the rear end of the projectile. This effects a considerable reduction of the maximal mass inertia forces. Tests carried out with the projectile according to the invention have shown that neither the previously mentioned cracks nor a separation of the base from the cylindrical portion of the projectile casing occurred. Rather, it was found that a considerable improvement in the sealing of the rear end of the projectile was obtained.

It is evident that the seal arrangement according to the invention is not limited to practice ammunition. The invention is advantageously applicable also to live ammunition, such as shells, tank destroying missiles, and the like.

In the following will be described two embodiments of the invention with reference to the accompanying drawing in which:

FIG. 1 illustrates a longitudinal sectional view of a projectile of the invention, and

FIG. 2 illustrates in a similar view a modified embodiment of the projectile of the invention.

Referring to FIG. 1, the disintegrating projectile 1 consists substantially of a projectile casing 2 preferably made of a plastic material, a filling enclosed in the projectile casing and consisting of cores of compacted metal powder 7, 8, and of a sealing arrangement 9 at the rear end of the projectile. The projectile casing 2 has a front portion 3 tapering out so as to form substantially a tip and a substantially cylindrical rear portion 4 integrally formed with the front portion 3 or suitably joined thereto. To the rear end of the casing 2 is fixedly attached a projectile base 6, which may be secured by an adhesive or a threaded screw connection or also by a welding connection. The particular connecting means is not illustrated in the drawing as it is irrelevant to the invention proper. The projectile base 6 may also be made as one unit with the cylindrical rear portion 4 of the casing 2 if a connection is provided within the region of the rear portion 4 or between the front portion 3 and the rear portion 4 of the casing 2. The cylindrical rear portion 4 of the projectile casing 2 is provided with a guide band 5 which has a somewhat larger outer diameter than the rear portion 4.

In the hollow space formed in the casing 2 is deposited the projectile filling in the form of cores 7 and 8 of compacted metal powder. The metal powder cores 7 and 8 are so arranged that the rear face of the core 8 is spaced a predetermined distance from the base 6 of the projectile. This hollow space between the rear face of the core 8 and the base 6 is filled with metal powder which together with the wall section of this part of the casing forms a semi-elastic seal h. The guide band 5 is arranged at the rear half part of the rear portion 4 of the casing 2 in such a manner that the rear edge of the guide band 5 is substantially flush with the rear end of the metal powder core 8. Thus, the metal powder 9 forming the semi-elastic seal is deposited behind the guide band 5 which due to its enlarged diameter constitutes a reinforcement of the wall of the rear portion 4 of the casing 2.

FIG. 2 illustrates a modified embodiment of the invention in which the part 4a of the wall of the rear portion 4 of the projectile casing 2 between the rear edge 5a of the guide band 5 and the base 6a has a reduced thickness compared with the wall thickness of the remaining portion of the casing which encloses the cores '7 and 3. This reduced wall thickness increases the elasticity of the seal 9.

Upon firing of the projectile, the propellant gases act upon the surface formed by the projectile base 6. Thereby the metal powder filling 9 is subjected to a limited compression resulting in a transmission of the forward thrust to the projectile filling, namely to the compacted metal powder cores 7 and 8, whereby the wall sections of the rear part of the rear portion 4 of the casing 2 are subjected to a limited expansion in the region of the metal powder filling 9. This ensures a satisfactory engagement of the projectile casing 2 with the wall of the barrel of the firearm and further a secure engagement of the guide band 5 with the grooves in the barrel.

The remaining parts of the projectile casing are of the conventional type and the disintegration of the projectile upon leaving the barrel of the firearm takes place in known manner.

What I claim is:

1. A disintegrating projectile, particularly a disintegrating bullet for practice ammunition, comprising a projectile casing having a tapering front end and being closed at its rear end by a fiat base, at least one core of compacted metal powder in said casing terminating in spaced relation from said fiat base, and a semi-elastic seal in the rear end of said projectile casing and filling the space formed between the rear end face of said core and said flat base.

2. A disintegrating projectile according to claim 1, in which said semi-elastic seal consists of metal powder loosely filling the hollow space formed between said rear end face of said core and said flat base.

3. A disintegrating projectile according to claim 1, including at least one cylindrical guide band on the outer circumference of said projectile casing, said projectile having a cylindrical rear end on the outer circumference of which said guide band is arranged so as to extend radially outwardly therefrom, the rear edge of said cylindrical guide band being arranged in the same plane as the rear end face of said compacted metal powder core in said casing.

4. A disintegrating projectile according to claim 11, in which the wall thickness of said projectile casing at the rear end thereof which contains said semi-elastic seal is less than the wall thickness in the remaining part of said casing.

5. A disintegrating projectile according to claim 1, including at least one cylindrical guide band on the outer circumference of said projectile casing, said projectile having a cylindrical rear end on the outer circumference of which said guide band is arranged so as to extend radially outwardly therefrom, the rear edge of said cylindrical guide band being arranged in the same plane as the rear end face of said compacted metal powder core in said casing, and the thickness of that portion of said casing which currounds the space filled with said semi-elastic seal being less than the wall thickness of the remaining portion of said casing.

References Cited UNITED STATES PATENTS 3,127,836 4/1964 Silva 1029l X 3,242,865 3/1966 Jungermann et al. 10291 3,338,167 8/1967 Jungermann et al. 102-92.7

FOREIGN PATENTS 965,889 8/1964 Great Britain.

ROBERT F. STAHL, Primary Examiner. 

